It is known to oscillate a scanning mirror about a scan axis at substantially uniform velocity. Such a system is disclosed, for example, in U.S. Pat. No. 3,671,766 of Howe. However, when such a mirror is carried by a space vehicle, the problem of absorbing its momentum and reversing its direction results in undesirable forces acting on the vehicle which may alter its attitude. It will also be apparent that, in such an application, it is desirable that there be minimum reversal time, minimum power consumption, and maximum reliability.
Accordingly, it is a principal object of the present invention to provide a system for driving a scanning element such as a mirror in such a manner as to cause minimum disturbance to the supporting vehicle.
Other objects are to provide such a system wherein the scanning element has a substantially uniform velocity with minimum reversal time, minimum power consumption, and maximum reliability. The manner in which these objects are achieved will be more apparent from the following description and appended claims.